A group of UN experts says it has found evidence to prove that Rwanda has engaged in military operations in the east of the Democratic republic of Congo including assisting the M23 rebel group.
The findings from a leaked report back up the assertion by DR Congo President Félix Tshisekedi that Rwanda has been supporting the rebels.
The Kigali government has repeatedly denied this, but has not yet responded to this latest report.
The re-emergence of the M23 rebel group in recent months has forced tens of thousands of civilians to flee their homes.
The leaked UN experts' report highlights the brutality of the conflict in eastern DR Congo.
It says in areas controlled by M23 rebels there has been pillaging, theft, extortion, torture, rape and killings.
The experts found evidence that the Rwandan armed forces provided troop reinforcements to help these rebels seize towns earlier this year.
The Congolese army is also heavily criticised.
The report says during its fight back against the M23 group, Congolese soldiers worked with various rebels including at times the FDLR - which is linked to the 1994 genocide in Rwanda.
Meanwhile, the M23 group says it is withdrawing from a strategic frontline position near the city of Goma.
The rebels said they would hand over Kibumba to an East African military force.
Last month presidents from the region called on the rebels to withdraw.
Source: BBC
